Now I'm on 44/54 of updating gstreamer, in the hope that this will solve qt-webkit failure.
A lot of new stuff is in. Python 2.7 for example, but also new bash, binutils, and this endless-compile llvm-3.1-r2.

I think I can set python 2.7 as default when all the other problem will be (hopefully) fixed.

I hope I can finish this run this evening, to be able to run a new 'emerge -uND world' or at least 'system' in the night.
I'll write down my progress.

!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

x11-libs/xcb-util:0

(x11-libs/xcb-util-0.3.6::gentoo, installed) pulled in by
<x11-libs/xcb-util-0.3.8 required by (x11-libs/startup-notification-0.10::gentoo, installed)

(x11-libs/xcb-util-0.3.9::gentoo, ebuild scheduled for merge) pulled in by
>=x11-libs/xcb-util-0.3.9 required by (x11-libs/xcb-util-wm-0.3.9::gentoo, ebuild scheduled for merge)
(and 3 more with the same problem)

media-libs/phonon:0

(media-libs/phonon-4.6.0-r1::gentoo, ebuild scheduled for merge) pulled in by
>=media-libs/phonon-4.6.0 required by (media-libs/phonon-gstreamer-4.6.2-r1::gentoo, ebuild scheduled for merge)
(and 1 more with the same problem)

(media-libs/phonon-4.3.80-r1::gentoo, installed) pulled in by
media-libs/phonon[xine?] required by (kde-base/phonon-kde-4.3.5::gentoo, installed)

media-libs/alsa-lib:0

(media-libs/alsa-lib-1.0.21a::gentoo, installed) pulled in by
media-libs/alsa-lib[alsa_pcm_plugins_extplug,alsa_pcm_plugins_ioplug] required by (net-wireless/bluez-4.63::gentoo, installed)

(media-libs/alsa-lib-1.0.25-r1::gentoo, ebuild scheduled for merge) pulled in by
>=media-libs/alsa-lib-1.0.25 required by (media-sound/alsa-utils-1.0.25-r1::gentoo, ebuild scheduled for merge)

After the .la incident of my last post, I had no other issue.
I'm on 73/225 of the last emerge -uND world, and I feel pretty good.
I just wonder why compilation is so SLOW. This is a 2.7GHz CPU after all.

On the other hand, I saw passing Samba 3, I did a small research and I found that now samba today has 34MB of sources (It tooks a couple of hours to compile).
I remember the first time I emerged it, years ago. Samba 1 was a really stupid library allowing to connect my Windows95 laptop for backup purposes, taking a couple of minutes on my old Atlon to get compiled.
Today, I still make backup (parts) of my Windows7 laptop almost in the same way.
Things change, people doesn't.

After the .la incident of my last post, I had no other issue.
I'm on 73/225 of the last emerge -uND world, and I feel pretty good.
I just wonder why compilation is so SLOW. This is a 2.7GHz CPU after all.

On the other hand, I saw passing Samba 3, I did a small research and I found that now samba today has 34MB of sources (It tooks a couple of hours to compile).
I remember the first time I emerged it, years ago. Samba 1 was a really stupid library allowing to connect my Windows95 laptop for backup purposes, taking a couple of minutes on my old Atlon to get compiled.
Today, I still make backup (parts) of my Windows7 laptop almost in the same way.
Things change, people doesn't.

how many cores? what exactly is the cpu brand? you know that cpu speed isn't the only factor when it comes to compilations._________________Only two things are infinite, the universe and human stupidity and I'm not sure about the former - Albert Einstein
ProjectFootball

ERROR: setup
CONFIG_IDE: should not be set. But it is.
CONFIG_BLK_DEV_BSG: is not set when it should be.
WARN: setup
Please check to make sure these options are set correctly.
Failure to do so may cause unexpected problems.

udev-171 does not support Linux kernel before version 2.6.32!
ERROR: setup
Your kernel version (2.6.31-gentoo-r6) is too old to run udev-171

udev cannot be restarted after emerging,
as your running kernel version (2.6.31-gentoo-r6) is too old.
You really need to use a newer kernel after a reboot!

This actually means I have to upgrade the kernel BEFORE reboot, isn't it?

Edit.:
Maybe the question was too stupid to get an answer. I prepared a 2.6.32 and a 3.5.7 kernel, using "make oldconfig", and then removing the CONFIG_IDE that udev was complaining about (that indeed was a mistake or was there since last hardware upgrade - my disk is /dev/sda).

Unfortunately during the night there were other file collisions about "solid" packages.
I had to unmerge some of these old packages this morning, then I was able to resume world emerging.
Maybe this is due to changes in ebuilds organization.
Yesterday I stopped the use of "--keep-going" because I note that a failure into a lib-kind ebuild emerge will cause subsequent failures in ebuild depending on it.
I have to say also that I'm not a fan of "COLLISION_IGNORE" feature, but probably I don't really know how it works.
Now, 4 packages left. I feel I can do it.

The most difficult thing was making work usb-devices mounting again, because of these kernel requirements of consolekit, udisks, etc.
This was the price of kissing hal goodbye. This took me sometime, but I get it work, in the end, without any agent.